Display device and manufacturing method thereof

ABSTRACT

A display device including: a substrate having display area and a non-display area; and an alignment mark disposed in the non-display area of the substrate. The alignment mark includes a quadrangular-shaped center portion and a plurality of measurement portions that surround the center portion, the plurality of measurement portions including four or more measurement portions, and each of the measurement portions including sides that are parallel with two sides of the quadrangular-shaped center portion.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from and the benefit of Korean PatentApplication No. 10-2018-0125943, filed on Oct. 22, 2018, which is herebyincorporated by reference for all purposes as if fully set forth herein.

BACKGROUND

Field

Exemplary embodiments of the invention relate generally to a displaydevice and a method for manufacturing the same, and more specifically,to a display device that includes an alignment mark that can measuremisalignment of a mask, and a method for manufacturing the displaydevice.

Discussion of the Background

Flat panel displays which are currently in use include a liquid crystaldisplay (LCD), a plasma display panel (PDP), an organic light emittingdiode (OLED) device, a field effect display (FED), an electrophoreticdisplay (EPD) device, and the like.

During a process for forming such a flat display device, variouspatterns are formed and an exposure device is used to form the patterns.The exposure device exposes an object according to a pattern formed in apattern mask.

However, as the display device is enlarged, since the size of thepattern mask is limited, it becomes more difficult to expose the displaysubstrate at one time by the pattern mask. Thus, a method for exposingthe display device by sequentially aligning masks on the display deviceis used.

The above information disclosed in this Background section is only forunderstanding of the background of the inventive concepts, and,therefore, it may contain information that does not constitute priorart.

SUMMARY

Exemplary embodiments of the present invention provide a display devicethat includes alignment marks that can measure misalignment of themasks, and a method for manufacturing the same.

Additional features of the inventive concepts will be set forth in thedescription which follows, and in part will be apparent from thedescription, or may be learned by practice of the inventive concepts.

An exemplary embodiment of the present invention provides: a substratethat has display area and a non-display area; and an alignment mark thatis disposed in the non-display area of the substrate. The alignment markincludes a quadrangular-shaped center portion and a plurality ofmeasurement portions that surround the center portion, the plurality ofmeasurement portions including four or more measurement portions, andeach of the measurement portions includes sides that are parallel withtwo sides of the quadrangular-shaped center portion.

One or more alignment marks may be disposed between the ¼ point and the¾ point of the non-display area in a first direction.

The plurality of measurement portions may include: a first measurementportion that includes sides that are parallel with a first side and afourth side of the quadrangular-shaped center portion and is disposedadjacent to the first side and the fourth side; a second measurementportion that includes sides that are parallel with the first side and asecond side of the quadrangular-shaped center portion and is disposedadjacent to the first side and the second side; a third measurementportion that includes sides that are parallel with the second side and athird side of the quadrangular-shaped center portion and is disposedadjacent to the second side and the third side; and a fourth measurementportion that includes sides that are parallel with the third side andthe fourth side of the quadrangular-shaped center portion and isdisposed adjacent to the third side and the fourth side.

A difference between a value obtained by subtracting a distance from thecenter portion to the third measurement portion in a second directionfrom a distance from the center portion to the first measurement portionin the second direction, and a value obtained by subtracting a distancefrom the center portion to the fourth measurement portion in the seconddirection from a distance from the center portion to the secondmeasurement portion in the second direction, may be about −0.8 μm toabout 0.8 μm.

A difference between a value obtained by subtracting a distance from thecenter portion to the third measurement portion in the first directionfrom a distance from the center portion to the first measurement portionin the first direction, and a value obtained by subtracting a distancefrom the center portion to the fourth measurement portion in the firstdirection from a distance from the center portion to the secondmeasurement portion in the first direction, may be about −0.8 μm to 0.8μm.

The center portion and the measurement portions may include differentmaterials.

The center portion may include the same material as a gate line in thedisplay area, and the measurement portions may include the same materialas a data line in the display area or the same material as a pixelelectrode in the display area.

The center portion may include the same material as a data line of thedisplay area, and the measurement portions may include the same materialas a pixel electrode of the display area.

The display device may further include a plurality of drivers that aredisposed in the non-display area, wherein the alignment marks may bedisposed between the plurality of drivers.

The non-display area may include an area where two or more masks areoverlapped with each other during a manufacturing process, and thealignment mark may be disposed in the mask-overlapped area.

A horizontal length of the alignment mark may be about 15 μm to about 30μm.

A vertical length of the alignment mark may be about 15 μm to about 30μm.

Another exemplary embodiment of the present invention provides: asubstrate having a display area and a non-display area; and an alignmentmark that is disposed in the non-display area of the substrate. Thealignment mark includes a quadrangular-shaped center portion and aplurality of measurement portions that surround the center portion, oneor more alignment marks are disposed between the ¼ point and the ¾ pointof the non-display area in the first direction, and the center portionand the measurement portions of the alignment mark include differentmaterials.

The measurement portions may include: a first measurement portion formedin the shape of a quadrangular ring that surrounds thequadrangular-shaped center portion; and a second measurement portionformed in the shape of a quadrangular ring that surrounds the firstmeasurement portion.

The measurement portions may include: a second measurement portion and athird measurement portion disposed on a virtual straight line that is inparallel with a first side of the quadrangular-shaped center portion,and are disposed apart from each other; a fourth measurement portion anda fifth measurement portion disposed on a virtual straight line that isin parallel with a second side of the quadrangular-shaped centerportion, and are disposed apart from each other; a sixth measurementportion and a seventh measurement portion disposed on a virtual straightline that is in parallel with a third side of the quadrangular-shapedcenter portion, and are disposed apart from each other; and an eighthmeasurement portion and a first measurement portion disposed on avirtual straight line that is in parallel with a fourth side of thequadrangular-shaped center portion, and are disposed apart from eachother.

The measurement portions may include: a fifth measurement portiondisposed in parallel with a first side of the quadrangular-shaped centerportion and a first measurement portion disposed between the first sideand the fifth measurement portion; a sixth measurement portion disposedin parallel with a second side of the quadrangular-shaped center portionand a second measurement portion disposed between the second side andthe sixth measurement portion; and an eighth measurement portiondisposed in parallel with a fourth side of the quadrangular-shapedcenter portion and a fourth measurement portion disposed between thefourth side and the eighth measurement portion.

The display device may further include a plurality of drivers that aredisposed in the non-display area, wherein the alignment marks may bedisposed between the plurality of drivers.

The non-display area may include an area where two or more masks areoverlapped with each other during a manufacturing process, and thealignment mark may be disposed in the mask-overlapped area.

The center portion may include the same material as a gate line or adata line of the display area, and the measurement portions may includethe same material as the data line of the display area or a pixelelectrode of the display area.

Another exemplary embodiment of the present invention provides a methodof manufacturing a display device, including: preparing a substrate tohave a display area and a non-display area; forming a center portiondisposed in the non-display area at the same time through the sameprocess as a process for forming a first conductive layer in the displayarea; forming a second conductive layer in the display area by using afirst mask, and forming a first measurement portion and a secondmeasurement portion that surround the center portion through the sameprocess as a process for forming the second conductive layer; andforming the second conductive layer by using a second mask in thedisplay area, and forming a third measurement portion and a fourthmeasurement portion that surround the center portion through the sameprocess as a process for forming the second conductive layer. The centerportion is formed in an area where the first mask and the second maskare overlapped with each other.

The center portion may be formed in the shape of a quadrangle, the firstmeasurement portion may include sides that are in parallel with a firstside and a second side of the quadrangular-shaped center portion, andmay be disposed adjacent to the first side and the fourth side, thesecond measurement portion may include sides that are in parallel withthe first side and a second side of the quadrangular-shaped centerportion, and may be disposed adjacent to the first side and the secondside, the third measurement portion may include sides that are inparallel with the second side and a third side of thequadrangular-shaped center portion, and may be disposed adjacent to thesecond side and the third side, and the third measurement portion mayinclude sides that are in parallel with the third side and the fourthside of the quadrangular-shaped center portion, and may be disposedadjacent to the third side and the fourth side.

The center portion and the measurement portions may include differentmaterials.

The center portion may include the same material as a gate line or adata line of the display area, and the measurement portions may includethe same material as the data line or a pixel electrode material of thedisplay area.

A difference between a value obtained by subtracting a distance from thecenter portion to the third measurement portion in a second directionfrom a distance from the center portion to the first measurement portionin the second direction, and a value obtained by subtracting a distancefrom the center portion to the fourth measurement portion in the seconddirection from a distance from the center portion to the secondmeasurement portion in the second direction, may be about −0.8 μm toabout 0.8 μm.

A difference between a value obtained by subtracting a distance from thecenter portion to the third measurement portion in a first directionfrom a distance from the center portion to the first measurement portionin the first direction, and a value obtained by subtracting a distancefrom the center portion to the fourth measurement portion in the firstdirection from a distance from the center portion to the secondmeasurement portion in the first direction, may be about −0.8 μm toabout 0.8 μm.

According to the exemplary embodiments, a display device that includesalignment marks that can measure misalignment of masks, and a method formanufacturing the same can be provided.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate exemplary embodiments of theinvention, and together with the description serve to explain theinventive concepts.

FIG. 1 schematically illustrates a display device according to anexemplary embodiment of the present invention.

FIG. 2 shows a configuration that uses a plurality of masks during amanufacturing process of a display panel.

FIG. 3 shows an alignment mark.

FIG. 4 and FIG. 5 show a shape of the alignment mark when the first maskand the second mask are misaligned.

FIG. 6 shows an alignment mark according to another exemplaryembodiment.

FIG. 7 shows a shape of an alignment mark according to another exemplaryembodiment of the present invention.

FIG. 8 shows a shape of an alignment mark according to another exemplaryembodiment of the present invention.

FIG. 9 shows a specific location of the alignment mark.

FIG. 10 shows a location of an alignment mark according to anotherexemplary embodiment of the present invention.

FIGS. 11, 12, 13, 14, and 15 are cross-sectional views of amanufacturing process of a display device according to an exemplaryembodiment of the present invention.

FIGS. 16, 17, 18, 19, and 20 show manufacturing processes of a displaydevice according to an exemplary embodiment of the present invention.

FIG. 21 is a pixel layout view of a display area according to anexemplary embodiment, and FIG. 22 is a cross-sectional view of thedisplay device of FIG. 21, taken along the line XXII-XXII′.

FIG. 23 is a cross-sectional view of a display panel according to anexemplary embodiment of the present invention.

DETAILED DESCRIPTION

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of various exemplary embodiments of the invention. As usedherein “embodiments” are non-limiting examples of devices or methodsemploying one or more of the inventive concepts disclosed herein. It isapparent, however, that various exemplary embodiments may be practicedwithout these specific details or with one or more equivalentarrangements. In other instances, well-known structures and devices areshown in block diagram form in order to avoid unnecessarily obscuringvarious exemplary embodiments. Further, various exemplary embodimentsmay be different, but do not have to be exclusive. For example, specificshapes, configurations, and characteristics of an exemplary embodimentmay be used or implemented in another exemplary embodiment withoutdeparting from the inventive concepts.

Unless otherwise specified, the illustrated exemplary embodiments are tobe understood as providing exemplary features of varying detail of someways in which the inventive concepts may be implemented in practice.Therefore, unless otherwise specified, the features, components,modules, layers, films, panels, regions, and/or aspects, etc.(hereinafter individually or collectively referred to as “elements”), ofthe various embodiments may be otherwise combined, separated,interchanged, and/or rearranged without departing from the inventiveconcepts.

The use of cross-hatching and/or shading in the accompanying drawings isgenerally provided to clarify boundaries between adjacent elements. Assuch, neither the presence nor the absence of cross-hatching or shadingconveys or indicates any preference or requirement for particularmaterials, material properties, dimensions, proportions, commonalitiesbetween illustrated elements, and/or any other characteristic,attribute, property, etc., of the elements, unless specified. Further,in the accompanying drawings, the size and relative sizes of elementsmay be exaggerated for clarity and/or descriptive purposes. When anexemplary embodiment may be implemented differently, a specific processorder may be performed differently from the described order. Forexample, two consecutively described processes may be performedsubstantially at the same time or performed in an order opposite to thedescribed order. Also, like reference numerals denote like elements.

When an element, such as a layer, is referred to as being “on,”“connected to,” or “coupled to” another element or layer, it may bedirectly on, connected to, or coupled to the other element or layer orintervening elements or layers may be present. When, however, an elementor layer is referred to as being “directly on,” “directly connected to,”or “directly coupled to” another element or layer, there are nointervening elements or layers present. To this end, the term“connected” may refer to physical, electrical, and/or fluid connection,with or without intervening elements. Further, the D1-axis, the D2-axis,and the D3-axis are not limited to three axes of a rectangularcoordinate system, such as the x, y, and z—axes, and may be interpretedin a broader sense. For example, the D1-axis, the D2-axis, and theD3-axis may be perpendicular to one another, or may represent differentdirections that are not perpendicular to one another. For the purposesof this disclosure, “at least one of X, Y, and Z” and “at least oneselected from the group consisting of X, Y, and Z” may be construed as Xonly, Y only, Z only, or any combination of two or more of X, Y, and Z,such as, for instance, XYZ, XYY, YZ, and ZZ. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items.

Although the terms “first,” “second,” etc. may be used herein todescribe various types of elements, these elements should not be limitedby these terms. These terms are used to distinguish one element fromanother element. Thus, a first element discussed below could be termed asecond element without departing from the teachings of the disclosure.

Spatially relative terms, such as “beneath,” “below,” “under,” “lower,”“above,” “upper,” “over,” “higher,” “side” (e.g., as in “sidewall”), andthe like, may be used herein for descriptive purposes, and, thereby, todescribe one elements relationship to another element(s) as illustratedin the drawings. Spatially relative terms are intended to encompassdifferent orientations of an apparatus in use, operation, and/ormanufacture in addition to the orientation depicted in the drawings. Forexample, if the apparatus in the drawings is turned over, elementsdescribed as “below” or “beneath” other elements or features would thenbe oriented “above” the other elements or features. Thus, the exemplaryterm “below” can encompass both an orientation of above and below.Furthermore, the apparatus may be otherwise oriented (e.g., rotated 90degrees or at other orientations), and, as such, the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting. As used herein, thesingular forms, “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. Moreover,the terms “comprises,” “comprising,” “includes,” and/or “including,”when used in this specification, specify the presence of statedfeatures, integers, steps, operations, elements, components, and/orgroups thereof, but do not preclude the presence or addition of one ormore other features, integers, steps, operations, elements, components,and/or groups thereof. It is also noted that, as used herein, the terms“substantially,” “about,” and other similar terms, are used as terms ofapproximation and not as terms of degree, and, as such, are utilized toaccount for inherent deviations in measured, calculated, and/or providedvalues that would be recognized by one of ordinary skill in the art.

Various exemplary embodiments are described herein with reference tosectional and/or exploded illustrations that are schematic illustrationsof idealized exemplary embodiments and/or intermediate structures. Assuch, variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, exemplary embodiments disclosed herein should notnecessarily be construed as limited to the particular illustrated shapesof regions, but are to include deviations in shapes that result from,for instance, manufacturing. In this manner, regions illustrated in thedrawings may be schematic in nature and the shapes of these regions maynot reflect actual shapes of regions of a device and, as such, are notnecessarily intended to be limiting.

In addition, in this specification, the phrase “on a plane” meansviewing a target portion from the top, and the phrase “on across-section” means viewing a cross-section formed by verticallycutting a target portion from the side.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure is a part. Terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the relevant art and should not be interpreted in anidealized or overly formal sense, unless expressly so defined herein.

Hereinafter, a display device according to an exemplary embodiment ofthe present invention will be described with reference to theaccompanying drawings.

FIG. 1 schematically shows a display device according to an exemplaryembodiment of the present invention. Referring to FIG. 1, a displaypanel 1000 of a display device according to an exemplary embodiment ofthe present invention includes a display area DA and a non-display areaNDA. The display area DA is an area where a plurality of pixelsincluding a pixel electrode connected with a transistor are disposed todisplay an image, and the non-display area NDA is an area where a driverand the like are disposed and thus, no image is displayed. Referring toFIG. 1, the display device according to the exemplary embodiment of thepresent invention includes one or more alignment marks AM.

In FIG. 1, the alignment marks AM are disposed close to opposite edgesof the display area DA in a second direction D2, but this is notrestrictive, and the alignment marks Am may be disposed only at one edgeof the display area DA. In FIG. 1, two alignment marks AM are disposedin an upper portion and two alignment marks AM are disposed in a lowerportion while disposing the display area DA therebetween, but this isjust an example. The number of alignment marks AM may be changeddepending on a number of masks used to form one layer (e.g., a pixelelectrode) in the display area DA. When two masks are used inmanufacturing of one layer in the display area DA, one or two alignmentmarks AM may be located, and this will be described in detail later. Inaddition, when three masks are used to form one layer of a displaydevice, two to four alignment marks AM may be located. That is, when nmasks are used to form one layer of the display device, n−1 to 2*(n−1)alignment marks may be located. The alignment mark may be located in anarea where masks are overlapped with each other in manufacturing of thedisplay area, and this will be described in detail later. A specificlocation relationship of the alignment marks AM will be described inmore detail later.

Referring to FIG. 1, the alignment mark AM includes aquadrangular-shaped center portion 700 and a plurality of measurementportions 710 a, 710 b, 710 c, and 710 d that are disposed whilesurrounding the center portion 700. The measurement portions may includea first measurement portion 710 a, a second measurement portion 710 b, athird measurement portion 710 c, and a fourth measurement portion 710 d.

Each of the measurement portions is disposed at a distance from thecenter portion 700. The center portion 700 can divide the alignment markAM into a first quadrant LA1, a second quadrant LA2, a third quadrantLA3, and a fourth quadrant LA4 with virtual vertical and horizontallines that cross the center of the quadrangular-shaped center portion700. In this case, the first measurement portion 710 a may be disposedin the first quadrant LA1, the second measurement portion 710 b may bedisposed in the second quadrant LA2, the third measurement portion 710 cmay be disposed in the third quadrant LA3, and the fourth measurementportion 710 d may be disposed in the fourth quadrant LA4.

The first measurement portion 710 a includes sides that are in parallelwith two sides of the quadrangular-shaped center portion 700. That is,the first measurement portion 710 a includes a side that is in parallelwith the first direction and a side that is in parallel with a seconddirection D2 that is perpendicular to the first direction D1. The sideof the first measurement portion 710 a, in parallel with the firstdirection D1, and the side of the first measurement portion 710 a, inparallel with the second direction D2, may meet at a corner with a rightangle. Similarly, the second measurement portion 710 b, the thirdmeasurement portion 710 c, and the fourth measurement portion 710 d eachincludes a side in parallel with the first direction D1 and a side inparallel with the second direction D2 with respect to thequadrangular-shaped center portion 700.

More specifically, the first measurement portion 710 a includes sidesthat are in parallel with a first side and a fourth side of thequadrangular-shaped center portion 700, and may be disposed adjacent tothe first side and the fourth side of the center portion 700. The secondmeasurement portion 710 b includes sides that are in parallel with thefirst side and a second side of the quadrangular-shaped center portion700, and may be disposed adjacent to the first side and the second sideof the center portion 700. The third measurement portion 710 c includessides that are in parallel with the second side and a third side of thequadrangular-shaped center portion 700, and may be disposed adjacent tothe second side and the third side of the center portion 700. The fourthmeasurement portion 710 d includes sides that are in parallel with thethird side and the fourth side of the quadrangular-shaped center portion700, and may be disposed adjacent to the third side and the fourth sideof the center portion 700.

Alignment of a mask can be determined in a manufacturing process bycomparing distances between the respective measurement portions 710 a,710 b, 710 c, and 710 d and the quadrangle of the center portion 700. Adetailed alignment determination method will be described later.

In each alignment mark AM, the center portion 700 and the measurementportions 710 a, 710 b, 710 c, and 710 d may include different materials.For example, the center portion 700 may include the same material as agate line of the display area DA, and the measurement portions 710 a,710 b, 710 c, and 710 d may include the same material as a gate line ofthe display area DA. Alternatively, the center portion 700 may includethe same material as the gate line or the data line of the display areaDA, and the measurement portions 710 a, 710 b, 710 c, and 710 d mayinclude the same material as a pixel electrode of the display area DA.

That is, the center portion 700 and the measurement portions 710 a, 710b, 710 c, and 710 d are formed in different stages, and the centerportion 700 may be formed earlier than the measurement portions 710 a,710 b, 710 c, 710 d.

As described, alignment of the mask can be determined during a processfor forming the display area DA by using a plurality of masks throughthe alignment mark AM that includes the center portion 700 and themeasurement portions 710 a, 710 b, 710 c, and 710 d. Accordingly,misalignment of the mask during the manufacturing process can beaccurately measured and corrected.

FIG. 2 shows a configuration in which a plurality of masks are usedduring a manufacturing process of the display panel. In case of adisplay panel of which a display area DA is large, it is difficult toform layers (e.g., a gate line, a data line, a pixel electrode, and thelike) that form the display area DA with a single mask. Thus, therespective layers can be formed by applying the plurality of maskssequentially to different areas.

As shown in FIG. 2, one layer can be patterned by using a first mask A,a second mask B, and a third mask C. In this case, an area where therespective masks A, B, and C are overlapped is formed. In FIG. 2, areasmarked by A+B and B+C are areas where the masks are overlapped with eachother, and these areas are patterned two times by different masks.

In this case, when the first mask A and the second mask B are misalignedin the overlapped area (e.g., A+B), a failure in a structure in thedisplay area DA may occur. That is, the overlapped area is exposed twotimes, by the first mask A and the second mask B, and when the firstmask A and the second mask B are misaligned, a short-circuit may occuror a pixel electrode cannot be normally formed in the overlapped area.

Thus, it is important to maintain alignment of the masks in theoverlapped area, and for this, it is important to accurately measure thedegree of misalignment in each mask alignment and patterning process.However, it is not easy to accurately measure misalignment of the mask,and it is not easy to determine in which direction the mask ismisaligned and how much the mask is misaligned by analyzing a structureof a final manufactured display panel.

However, the display device according to the present exemplaryembodiment includes an alignment mark AM that is simultaneously formedthrough a patterning process using each mask, and an alignment error ofthe mask can be accurately calculated by measuring a distance betweenthe center portion 700 and measurement portions 710 a, 710 b, 710 c, and710 d of the alignment mark AM.

As shown in FIG. 2, the alignment marks AM are disposed at areas wherethe masks are overlapped with each other (e.g., A+B, B+C) because eachportion of the alignment mark AM is formed simultaneously through apattern forming process by a different mask.

FIG. 3 shows only an alignment mark AM. Referring to FIG. 3, thealignment mark AM includes a quadrangular-shaped center portion 700 anda plurality of measurement portions 710 a, 710 b, 710 c, and 710 d thatsurround the center portion 700.

The first measurement portion 710 a and the third measurement portion710 c are formed simultaneously with a patterning process of a displayarea DA by a first mask A. In addition, the second measurement portion710 b and the fourth measurement portion 710 d are formed simultaneouslywith a patterning process of the display area DA by a second mask B.Thus, a difference between a distance from the first measurement portion710 a to the center portion 700 and a distance from the thirdmeasurement portion 710 c to the center portion 700, and a differencebetween a distance from the second measurement portion 710 b to thecenter portion 700 and a distance from the fourth measurement portion710 d to the center portion 700, are compared to accurately measure analignment error of the mask.

The alignment mark AM shown in FIG. 3 is an alignment mark of a displaydevice where misalignment does not occur. In this case, a value obtainedby subtracting a distance ({circle around (b)}) from the thirdmeasurement portion 710 c to the center portion 700 in a first directionD1 from a distance ({circle around (2)}) from the first measurementportion 710 a to the center portion 700 in the first direction D1 and avalue obtained by subtracting a distance ({circle around (d)}) from thefourth measurement portion 710 d to the center portion 700 in the firstdirection D1 from a distance ({circle around (4)}) from the secondmeasurement portion 710 b to the center portion 700 in the firstdirection D1 are the same.

That is, in FIG. 3, {circle around (2)}−{circle around (b)}={circlearound (4)}−{circle around (d)}, and in this case, it can be determinedthat the first mask and the second mask are aligned without an error inthe first direction D1. Substantially, the masks are considered as beingaligned without an error when a difference between a value of {circlearound (2)}−{circle around (b)} and a value of {circle around(4)}−{circle around (d)} is less than 0.8 μm. That is, in the displaydevice according to the present exemplary embodiment, a differencebetween the value of {circle around (2)}−{circle around (b)} and thevalue of {circle around (4)}−{circle around (d)} of the alignment markAM may be about −0.8 μm to about 0.8 μm.

Similarly, a value obtained by subtracting a distance {circle around(a)} between the third measurement portion 710 c and the center portion700 in the second direction D2 from a distance {circle around (1)}between the first measurement portion 710 a and the center portion 700in the second direction D2 equals a value obtained by subtracting adistance {circle around (c)} between the fourth measurement portion 710d and the center portion 700 in the second direction D2 from a distance{circle around (3)} between the second measurement portion 710 b and thecenter portion 700 in the second direction.

That is, in FIG. 3, {circle around (1)}−{circle around (a)}={circlearound (3)}−{circle around (c)}, and in this case, the first mask andthe second mask area are determined to be aligned without an error inthe second direction D2. Substantially, it is determined that amisalignment does not occur when a difference between the value of{circle around (1)}−{circle around (a)} and the value of {circle around(3)}−{circle around (c)} is less than 0.8 μm. That is, in the displaydevice according to the present exemplary embodiment, the value of{circle around (1)}−{circle around (a)} and the value of {circle around(3)}−{circle around (c)} may be −0.8 μm to 0.8 μm.

Accordingly, when {circle around (2)}−{circle around (b)}={circle around(4)}−{circle around (d)} and {circle around (1)}−{circle around(a)}={circle around (3)}−{circle around (c)}, the first mask and thesecond mask are determined to be aligned without an error in the firstdirection D1 and the second direction D2. In addition, even when adifference between a value of {circle around (2)}−{circle around (b)}and a value of {circle around (4)}−{circle around (d)} is −0.8 μm to 0.8μm and a difference between a value of {circle around (1)}−{circlearound (a)} and a value of {circle around (3)}−{circle around (c)} is−0.8 μm to 0.8 μm, the first mask and the second mask are determined tobe aligned without an error.

In FIG. 3, a size L1 of the alignment mark AM in the first direction D1may be 15 um to 30 μm. In addition, a size L2 of the alignment mark AMin the second direction D2 may be 15 um to 30 μm.

FIG. 4 and FIG. 5 show a shape of the alignment mark when the first maskand the second mask are misaligned.

In the alignment mark shown in FIG. 4, {circle around (1)}−{circlearound (a)}<{circle around (3)}−{circle around (c)}. Thus, the secondmask used in forming of the second measurement portion 710 b and thefourth measurement portion 710 d is determined to be misaligned in thesecond direction D2. In addition, the degree of misalignment can bespecifically determined through comparison of the value of {circlearound (1)}−{circle around (a)} and the value of {circle around(3)}−{circle around (c)}.

The alignment mark shown in FIG. 5 is {circle around (2)}−{circle around(b)}>{circle around (4)}−{circle around (d)}. Thus, a first mask used informing of the first measurement portion 710 a and the secondmeasurement portion 710 c are determined to be misaligned in the firstdirection D1. Specifically, the degree of misalignment can bespecifically determined through comparison of the value of {circlearound (2)}−{circle around (b)} and the value of {circle around(4)}−{circle around (d)}.

In FIG. 1 to FIG. 5, the quadrangular-shaped center portion 700 and theL-shaped measurement portions 710 a, 710 b, 710 c, and 710 d are shown,but the shape of the alignment mark AM is not limited thereto.

The measurement portions may have any shape as long as the distances{circle around (1)}, {circle around (2)}, {circle around (3)}, {circlearound (4)}, {circle around (a)}, {circle around (b)}, {circle around(c)}, and {circle around (d)} shown in FIG. 3 with respect to the centerportion 700 can be measured. The distances {circle around (1)}, {circlearound (2)}, {circle around (a)}, and {circle around (b)} are distancesbetween each portion of the measurement portions formed through the sameprocess as the first mask A, and the distances {circle around (3)},{circle around (4)}, {circle around (c)}, and {circle around (d)} aredistances between each portion of the measurement portions formedthrough the same process as the second mask B and the center portion700.

For example, the alignment mark AM may have a shape as shown in FIG. 6.FIG. 6 shows an alignment mark according to another exemplaryembodiment. Referring to FIG. 6, the alignment mark AM includes a firstmeasurement portion 711 a, a second measurement portion 711 b, a thirdmeasurement portion 711 c, a fourth measurement portion 711 d, a fifthmeasurement portion 711 e, a sixth measurement portion 711 f, a seventhmeasurement portion 711 g, and an eighth measurement portion 711 h thatsurround a quadrangular-shaped center portion 700. The first measurementportion 711 a, the second measurement portion 711 b, the fifthmeasurement portion 711 e, and the sixth measurement portion 711 f maybe formed through the same process, such as a patterning process by afirst mask, and the third measurement portion 711 c, the fourthmeasurement portion 711 d, the seventh measurement portion 711 g, andthe eighth measurement portion 711 h may be formed through the sameprocess, such as a patterning process by a second mask.

In this case, similar to FIG. 3, an alignment error in the firstdirection D1 can be determined through comparison between a value of{circle around (2)}−{circle around (b)} and a value of {circle around(4)}−{circle around (d)}, and an alignment error in the second directionD2 can be determined through comparison between a value of {circlearound (1)}−{circle around (a)} and a value of {circle around(3)}−{circle around (c)}.

FIG. 7 shows a shape of an alignment mark AM according to anotherexemplary embodiment of the present invention. Referring to FIG. 7, analignment mark AM according to the present exemplary embodiment includesa center portion 700, a first measurement portion 721 that surrounds thecenter portion 700, and a second measurement portion 722 that surroundsthe first measurement portion 721.

The first measurement portion 721 is formed through the same process asa patterning process by a first mask, and the second measurement portion722 is formed through the same process as a patterning process by asecond mask. In the exemplary embodiment of FIG. 7, similar to FIG. 3,an alignment error in a first direction D1 can be determined throughcomparison between a value of {circle around (2)}−{circle around (b)}and a value of {circle around (4)}−{circle around (d)}, and an alignmenterror in a second direction D2 can be determined through comparisonbetween a value of {circle around (1)}−{circle around (a)} and a valueof {circle around (3)}−{circle around (c)}.

FIG. 8 shows a shape of an alignment mark AM according to anotherexemplary embodiment of the present invention. Referring to FIG. 8, analignment mark AM according to the present exemplary embodiment includesa center portion 700, a first measurement portion 730 a, a secondmeasurement portion 730 b, a third measurement portion 730 c, and afourth measurement portion 730 d that surround the center portion 700.In addition, the alignment mark AM includes a fifth measurement portion730 e, a sixth measurement portion 730 f, a seventh measurement portion730 g, and an eighth measurement portion 730 h that surround the firstmeasurement portion 730 a, the second measurement portion 730 b, thethird measurement portion 730 c, and the fourth measurement portion 730d.

In the exemplary embodiment of FIG. 8, similar to FIG. 3, an alignmenterror in a first direction D1 can be determined through comparisonbetween a value of {circle around (2)}−{circle around (b)} and a valueof {circle around (4)}−{circle around (d)}, and an alignment error in asecond direction D2 can be determined through comparison between a valueof {circle around (1)}−{circle around (a)} and a value of {circle around(3)}−{circle around (c)}.

Such an alignment mark AM may be disposed in the non-display area NDA ofthe display panel 1000. Specifically, the alignment mark AM may bedisposed between a plurality of drivers 800 of the non-display area NDA.FIG. 9 shows a specific location of the alignment mark AM.

Referring to FIG. 9, the plurality of drivers 800 are disposed in thenon-display area NDA, and wires are stretched in a fan-out form from thedrivers 800, and are thus connected to the display area DA. Thus, asshown in FIG. 9, the alignment marks AM may be disposed in spacesbetween the plurality of drivers 800 and the wires connected with thedrivers 800.

The alignment marks may be disposed in areas where a plurality of masksused in manufacturing of the display area DA are overlapped with eachother. Specifically, one or more alignment marks AM may be disposed in anon-display area NDA that neighbors the ¼ point to the ¾ point in awidth of the display area DA in the first direction. This is becausewhen two or more masks are used, a mask overlapped area is located atthe ¼ to ¾ point of the display area DA in the first direction. In FIG.9, the alignment marks AM are disposed only at one side of the displayarea DA, but the alignment marks AM may be disposed at opposite sides,with the display area DA therebetween.

In addition, in FIG. 9, only one alignment mark AM is disposed per maskoverlapped area, but the number of alignment marks is not limitedthereto.

In FIG. 9, the alignment mark AM is disposed in the display panel 1000,but the alignment mark AM may be disposed outside the display panel1000. FIG. 10 shows a mother substrate 2000 in which alignment marks AMare disposed outside a display panel 1000. Referring to FIG. 10,alignment marks AM are disposed in a mother substrate 2000 where aplurality of display panels 1000 are manufactured, and may not bedisposed on the display panel 1000. In this case, the alignment marksare used to determine alignment of masks and then removed through acutting process and the like. Thus, the alignment marks may not bedisposed on a final display panel 1000.

Next, a method for manufacturing a display device according to anexemplary embodiment of the present invention will be described withreference to the accompanying drawings. FIG. 11 to FIG. 15 arecross-sectional views of a manufacturing process of a display deviceaccording to an exemplary embodiment of the present invention.

First, a substrate 110 that includes a display area DA and a non-displayarea NDA is prepared. The display area DA is an area where a transistor,a pixel electrode, and the like are located.

Referring to FIG. 12, center portions 700 are formed in the non-displayarea NDA that is adjacent to the display area DA. In this case, thecenter portions 700 may be formed through the same process as that forforming a gate line in the display area DA. Thus, the center portion 700may include the same material as the gate line in the display area DA.

Areas where the center portions 700 are formed are those where masks areoverlapped with each other in the subsequent process. Thus, exactlocations of the center portions 700 may be changed depending on thenumber of masks used in a process for manufacturing one layer of adisplay panel. Specifically, when two masks are used in the process forforming one layer of the display panel, the center portion 700 may belocated near the ½ point of the display panel in the first direction D1.In addition, when three masks are used in the process for forming onelayer of the display panel, the center portions 700 may be located nearthe ⅓ point and the ⅔ point, respectively, in the first direction D1 ofthe display panel. Accordingly, when two or more masks are used, one ormore center portions 700 may be located between the ¼ point and the ¾point of the display panel in the first direction D1.

Next, referring to FIG. 13, one layer of the display area DA is formedby using a first mask A. The layer of the display area formed in thisstage may be a conductive layer including a data line. Alternatively,the layer may be an electrode layer including a pixel electrode. In thiscase, a first measurement portion 710 a and a third measurement portion710 c are formed together at corners of each of the center portion 700.The first measurement portion 710 a and the third measurement portion710 c include the same material as a layer patterned in the display areaby using the first mask A. That is, when a data line is patterned in thedisplay area DA by using the first mask A, the first measurement portion710 a and the third measurement portion 710 c include a data linematerial, and when a pixel electrode is patterned in the display area DAby using the first mask A, the first measurement portion 710 a and thethird measurement portion 710 c include a pixel electrode material.

FIG. 13 exemplarily illustrates a structure in which the firstmeasurement portion 710 a and the third measurement portion 710 c areL-shaped, but the inventive concepts are not so limited. The firstmeasurement portion 710 a and the third measurement portion 710 c mayhave various shapes while having a constant distance from the centerportion 700.

Next, referring to FIG. 14, one layer is formed in the display area byusing the second mask B, and the second measurement portion 710 b andthe fourth measurement portion 710 d are simultaneously formed. In thiscase, an area where the second measurement portion 710 b and the fourthmeasurement portion 710 d are formed is an area where the first mask Aand the second mask B are overlapped with each other. A layer formed inthe display area by the second mask B is the same as the layer formed bythe first mask A. Thus, the second measurement portion 710 b and thefourth measurement portion 710 d also include the same material as thefirst measurement portion 710 a and the third measurement portion 710 c.Referring to FIG. 14, the second measurement portion 710 b and thefourth measurement portion 710 d may be formed at corners where thefirst measurement portion 710 a and the third measurement portion 710 care formed among corners of the quadrangular-shaped center portion 700.

Next, referring to FIG. 15, one layer is formed in the display area byusing the third mask C, and the first measurement portion 710 a and thethird measurement portion 710 c are simultaneously formed. In this case,the layer formed by the third mask C is the same as the layer formed bythe first mask A and the second mask B. Through such a process, analignment mark AM, including a center portion 700 and measurementportions 710 a, 710 b, 710 c, and 710 d, is formed.

FIG. 11 to FIG. 15 show a process for manufacturing the display devicewhere the alignment marks are disposed in the non-display area of thedisplay panel. Referring to FIG. 16 to FIG. 20, a process formanufacturing a display device in which alignment marks are disposedoutside a display panel will be described. FIG. 16 to FIG. 20 showmanufacturing processes of a display device according to an exemplaryembodiment.

Referring to FIG. 16, a mother substrate 2000 where a display panel 1000that includes a display area DA and a non-display area NDA is prepared.FIG. 16 illustrates only one display panel 1000 for convenience ofdescription, but a plurality of display panels 1000 may be disposed inthe mother substrate 2000.

Next, referring to FIG. 17, center portions 700 are formed. In thiscase, the center portions 700 may be formed through the same process asthat for forming a gate line in the display area DA. Thus, the centerportion 700 may include the same material as the gate line in thedisplay area DA.

A location where the center portion 700 is formed is an area where masksare overlapped with each other. When two or more masks are used in thedisplay panel 1000, one or more center portions 700 may be disposedbetween the ¼ point and the ¾ point of the display panel 1000 in a firstdirection.

Next, referring to FIG. 18, one layer is formed in the display area DAby using a first mask A. The layer formed in this case may be a dataline or a pixel electrode. In this case, a first measurement portion 710and a third measurement portion 710 c are formed together at corners ofthe center portion 700. The first measurement portion 710 a and thethird measurement portion 710 c include the same material as the layerpatterned in the display area DA by using the first mask A.

Next, referring to FIG. 19, one layer is formed in the display area DAby using a second mask B, and a second measurement portion 710 b and afourth measurement portion 710 d are simultaneously formed. In thiscase, an area where the second measurement portion 710 b and the fourthmeasurement portion 710 d are formed is an area where the first mask Aand the second mask B are overlapped with each other. The secondmeasurement portion 710 b and the fourth measurement portion 710 d alsoinclude the same material as the first measurement portion 710 a and thethird measurement portion 710 c. Referring to FIG. 19, the secondmeasurement portion 710 b and the fourth measurement portion 710 d maybe formed in an area where the first measurement portion 710 a and thethird measurement portion 710 c are not formed among corners of thequadrangular-shaped center portion 700.

Next, referring to FIG. 20, one layer is formed in the display area DAby using a third mask C, and the first measurement portion 710 a and thethird measurement portion 710 c are simultaneously formed. In this case,the layer formed by the third mask C is also the same as the layersformed by the first mask A and the second mask B. Through such aprocess, an alignment AM including the center portion 700 and themeasurement portions 710 a, 710 b, 710 c, and 710 d is formed.

Next, a display device can be formed by cutting the display panel 1000in the mother substrate 2000. Thus, the alignment marks are not disposedin the finally manufactured display panel 1000. That is, the alignmentmarks can be disposed only during a manufacturing process.

In FIG. 11 to FIG. 15 and FIG. 16 to FIG. 20, three masks are used inthe manufacturing process, but the alignment marks AM can be formedthrough the same process even if the number of masks is changed. Thatis, the number of alignment marks AM is changed depending on the numberof masks, and a specific formation principle is the same as thatdescribed with reference to FIG. 11 to FIG. 15 and FIG. 16 to FIG. 20.In addition, in FIG. 11 to FIG. 15 and FIG. 16 to FIG. 20, themanufacturing process is described using an example of a structure inwhich the alignment mark AM has the same shape as the alignment markshown in FIG. 1, but the alignment mark AM may be manufactured through aprocess similar to that shown in FIG. 11 to FIG. 15 and FIG. 16 to FIG.20 even when the alignment mark has the shape shown in FIG. 6 to FIG. 8.That is, a part of a measurement portion that forms each alignment markis formed through the same process as that of a first mask, and anotherpart may be formed through the same process as that of a second mask.

Next, a pixel in a display device of a display panel will be describedin detail with reference to the drawings.

FIG. 21 is a pixel layout view of a display area according to anexemplary embodiment, and FIG. 22 is a cross-sectional view of thedisplay device of FIG. 21, taken along the line XXII-XXII.

Referring to FIG. 21 and FIG. 22, the display panel includes a firstsubstrate 100, a second substrate 200 that overlaps the first substrate100, and a liquid crystal layer 3 that is disposed between the firstsubstrate 100 and the second substrate 200 and includes liquid crystalmolecules 31.

First, the first substrate 100 will be described. A gate conductor thatincludes gate lines 121 and a gate electrode 124 is disposed on one sideof a first base substrate 110 that is made of transparent glass orplastic.

The gate line 121 may extend in a first direction D1. The gate conductormay include various metals or conductors, and may be formed in amultilayered structure. A gate insulation layer 140 is disposed betweenthe gate conductor and the liquid crystal layer 3. The gate insulationlayer 140 may include an inorganic insulating material.

A semiconductor layer 154 is disposed on one side of the gate insulationlayer 140.

Data lines 171 are disposed between the semiconductor layer 154 and theliquid crystal layer 3, and extend in a second direction DR2 and thus,cross the gate lines 121. A source electrode 173 extends from the dataline 171 and thus, may overlap the gate electrode 124. A drain electrode175 is separated from the data lines 171 and, as shown in FIG. 21, thedrain electrode 175 may be formed in the shape of a bar extending towarda center of the source electrode 173.

A part of the semiconductor layer 154 may not overlap the data line 171and the drain electrode 175 in an area between the source electrode 173and the drain electrode 175. The semiconductor layer 154 may havesubstantially the same planar shape as the data line 171 and the dataelectrode 175, excluding such a non-overlapped portion.

One gate electrode 124, one source electrode 173, and one drainelectrode 175 form one thin film transistor together with thesemiconductor layer 154, and a channel of the thin film transistor is anarea for the semiconductor layer 154 between the source electrode 173and the drain electrode 175.

A passivation layer 180 is disposed between the source electrode 173 anddrain electrode 175 and the liquid crystal layer 3. The passivationlayer 180 may include an inorganic insulation material, such as asilicon nitride or a silicon oxide, an organic insulation material, alow dielectric constant insulation material, and the like.

The passivation layer 180 includes a contact hole 185 that overlaps apart of the drain electrode 175.

A first electrode 191 is disposed between the passivation layer 180 andthe liquid crystal layer 3. The first electrode 191 is physically andelectrically connected with the drain electrode 175 through the contacthole 185, and receives a data voltage from the drain electrode 175. Thefirst electrode 191 may be a pixel electrode.

The second substrate 200 includes a second base substrate 210, a lightblocking member 220, a color filter 230, a planarization layer 250, anda second electrode 270.

The light blocking member 220 and the color filter 230 are disposed inthe second base substrate 210. The light blocking member 220 may extendin the second direction D2, while overlapping the data line 171.Although it is not illustrated, the light blocking member 220 mayfurther include a horizontal portion that extends in the first directionD1 while overlapping the gate line 121. However, the light blockingmember 220 can be omitted.

Next, the planarization layer 250 that covers the light blocking member220 and the color filter 230 is disposed. The planarization layer 250may be omitted depending on exemplary embodiments. The second electrode270 is disposed, while overlapping the planarization layer 250. Thesecond electrode 270 may be a common electrode.

Hereinabove, the display area DA has been exemplarily described as aliquid crystal display (LCD), but the display area DA may be a displaydevice that includes an organic light emitting element.

FIG. 23 is a cross-sectional view of a display panel according to anexemplary embodiment of the present invention. Referring to FIG. 23, abuffer layer 111 that is made of a silicon oxide or a silicon nitride isdisposed on a first base substrate 110.

A semiconductor layer is disposed on the buffer layer 111. Thesemiconductor layer 154 includes a source area 153, a drain area 155,and a channel area 151. The source area 153 and the drain area 155 aredoped with a p-type impurity, and the channel area 151 is disposedbetween the source area 153 and the drain area 155.

A gate insulation layer 140 is disposed on the semiconductor layer 154and the buffer layer 111, and may include a silicon oxide or a siliconnitride. The gate electrode 124 is disposed on the gate insulation layer140, while overlapping the channel area 151 of the semiconductor layer154.

An interlayer insulation layer 160 is disposed on the gate electrode 124and the gate insulation layer 140. The interlayer insulation layer 160includes a first contact hole 165 and a second contact hole 163.

A data conductor that includes a data line 171, a source electrode 173,and a drain electrode 175 is disposed on the interlayer insulation layer160.

The drain electrode 175 is connected with the drain area 155 through thefirst contact hole 165. In addition, the source electrode 173 isconnected with the source area 153 through the second contact hole 163.

A passivation layer 180 is disposed on the data conductors 171, 173, and175 and the interlayer insulation layer 160, and includes a contact hole185.

A first electrode 191 is disposed on the passivation layer. The firstelectrode 191 may be a pixel electrode. The first electrode 191 isconnected with the drain electrode 175 through the contact hole 185. Abarrier rib 361 is disposed on the passivation layer 180. A lightemitting element layer 370 is disposed, while overlapping the firstelectrode 191, and a second electrode 270 is disposed to be overlappedwith the light emitting element layer 370. The second electrode 270 maybe a common electrode.

In this case, the first electrode 191 may be an anode, which is a holeinjection electrode, and the second electrode 270 may be a cathode,which is an electron injection electrode. However, the inventiveconcepts are not so limited, and the first electrode 191 may be acathode and the second electrode 270 may be an anode depending on adriving method of the display device.

The light emitting element layer 370 may include an emission layer, anelectron transport layer, and a hole transport layer.

An encapsulation layer 390 is disposed while overlapping the secondelectrode 270. The encapsulation layer 390 may include an organicmaterial or an inorganic material, and an organic material and aninorganic material may be alternately stacked. The encapsulation layer390 can protect the display device from external moisture, heat, andother contaminants.

Although certain exemplary embodiments and implementations have beendescribed herein, other embodiments and modifications will be apparentfrom this description. Accordingly, the inventive concepts are notlimited to such embodiments, but rather to the broader scope of theappended claims and various obvious modifications and equivalentarrangements as would be apparent to a person of ordinary skill in theart.

What is claimed is:
 1. A display device comprising: a substrate having adisplay area and a non-display area; and an alignment mark disposed inthe non-display area of the substrate, wherein: the alignment markcomprises a quadrangular-shaped center portion and a plurality ofmeasurement portions that are separated from each other and surround thecenter portion; each of the measurement portions comprises sides thatare parallel with two sides of the quadrangular-shaped center portion;and at least one of the measurement portions have an L-shape.
 2. Thedisplay device of claim 1, wherein one or more alignment marks aredisposed between the ¼ point and the ¾ point of the non-display area ina first direction.
 3. The display device of claim 1, wherein theplurality of measurement portions comprise: a first measurement portioncomprising sides that are in parallel with a first side and a fourthside of the quadrangular-shaped center portion and is disposed adjacentto the first side and the fourth side; a second measurement portioncomprising sides that are in parallel with the first side and a secondside of the quadrangular-shaped center portion and is disposed adjacentto the first side and the second side; a third measurement portioncomprising sides that are in parallel with the second side and a thirdside of the quadrangular-shaped center portion and is disposed adjacentto the second side and the third side; and a fourth measurement portioncomprising sides that are in parallel with the third side and the fourthside of the quadrangular-shaped center portion and is disposed adjacentto the third side and the fourth side.
 4. The display device of claim 3,wherein a difference between a value obtained by subtracting a distancefrom the center portion to the third measurement portion in a seconddirection from a distance from the center portion to the firstmeasurement portion in the second direction, and a value obtained bysubtracting a distance from the center portion to the fourth measurementportion in the second direction from a distance from the center portionto the second measurement portion in the second direction, is about −0.8μm to about 0.8 μm.
 5. The display device of claim 3, wherein adifference between a value obtained by subtracting a distance from thecenter portion to the third measurement portion in the first directionfrom a distance from the center portion to the first measurement portionin the first direction, and a value obtained by subtracting a distancefrom the center portion to the fourth measurement portion in the firstdirection from a distance from the center portion to the secondmeasurement portion in the first direction, is about −0.8 μm to 0.8 μm.6. The display device of claim 1, wherein the center portion and themeasurement portions comprise different materials from each other. 7.The display device of claim 1, wherein: the center portion comprises thesame material as a gate line in the display area; and the measurementportions comprise the same material as a data line in the display areaor the same material as a pixel electrode in the display area.
 8. Thedisplay device of claim 1, wherein: the center portion comprises thesame material as a data line of the display area; and the measurementportions comprise the same material as a pixel electrode of the displayarea.
 9. The display device of claim 1, further comprising a pluralityof drivers disposed in the non-display area, wherein the alignment marksare disposed between the plurality of drivers.
 10. The display device ofclaim 1, wherein the non-display area comprises an area where two ormore masks are overlapped with each other during a manufacturingprocess, and the alignment mark is disposed in the mask-overlapped area.11. The display device of claim 1, wherein a horizontal length of thealignment mark is about 15 μm to about 30 μm.
 12. The display device ofclaim 1, wherein a vertical length of the alignment mark is about 15 μmto about 30 μm.
 13. A display device comprising: a substrate having adisplay area and a non-display area; and an alignment mark disposed inthe non-display area of the substrate, wherein: the alignment markcomprises a quadrangular-shaped center portion and a plurality ofelongated measurement portions that are separated from each other andsurround the center portion; the center portion and the measurementportions of the alignment mark comprise different materials; and themeasurement portions comprise: a second measurement portion and a thirdmeasurement portion that are disposed on a same virtual straight linethat is in parallel with a first side of the quadrangular-shaped centerportion, and are disposed apart from each other, and the virtualstraight line is in parallel with the elongated direction of the secondmeasurement portion and the third measurement portion; a fourthmeasurement portion and a fifth measurement portion that are disposed ona same virtual straight line that is in parallel with a second side ofthe quadrangular-shaped center portion, and are disposed apart from eachother, and the virtual straight line is in parallel with the elongateddirection of the fourth measurement portion and the fifth measurementportion; a sixth measurement portion and a seventh measurement portionthat are disposed on a same virtual straight line that is in parallelwith a third side of the quadrangular-shaped center portion, and aredisposed apart from each other, and the virtual straight line is inparallel with the elongated direction of the sixth measurement portionand the seventh measurement portion; and an eighth measurement portionand a first measurement portion that are disposed on a same virtualstraight line that is in parallel with a fourth side of thequadrangular-shaped center portion, and are disposed apart from eachother, and the virtual straight line is in parallel with the elongateddirection of the eighth measurement portion and the first measurementportion.
 14. The display device of claim 13, further comprising aplurality of drivers that are disposed in the non-display area, whereinthe alignment marks are disposed between the plurality of drivers. 15.The display device of claim 13, wherein: the non-display area comprisesan area where two or more masks are overlapped with each other during amanufacturing process; and the alignment mark is disposed in themask-overlapped area.
 16. The display device of claim 13, wherein: thecenter portion comprises the same material as a gate line or a data lineof the display area; and the measurement portions comprise the samematerial as the data line of the display area or a pixel electrode ofthe display area.